i) Field of the Invention
This invention relates to novel syntheses of aromatic tertiary amines and aromatic enamines as well as to novel aromatic enamines and the syntheses therefrom of deoxybenzoins and benzils.
ii) Description of Prior Art
The "anil" reaction of Scheme 1 developed by Siegrist (A. E. Siegrist et al, Advances in Heterocyclic Chemistry 23, 171 (1978)) has been utilized for the synthesis of a large number of substituted stilbenes (3) by the condensation of an anil (1) with a methyl-containing aromatic compound (2). The aryl groups Ar, Ar' and Ar" can be hydrocarbon or a wide variety of heterocyclic groups. the reaction ##STR1## takes place in the presence of strong bases such as potassium tert-butoxide or powdered potassium hydroxide in N,N-dimethylformamide solution at 25.degree.-100.degree. C. and since the aromatic amine (4) is the coproduct in the reaction the strongly basic conditions are maintained in the reaction. The reaction has also been utilized in Scheme 2 for the synthesis of 2-phenylbenzofuran (6) by the intramolecular condensation of the Schiff's ##STR2## base (5) derived from 1-formyl-2-benzyloxybenzene and aniline, (W. Sahm et al Justus Liebigs Ann. Chem., 523 (1974).
Aromatic tertiary amines have previously been described for the production of charge transport layers in xerography in U.S. Pat Nos. 4,115,116; 4,047,948; 4,047,949; 4,081,274 and 4,232,103 and polymers containing these amine moieties have been synthesized (U.S. Pat. Nos. 4,806,443 and 4,806,444).